REFLECTOR: What's the calculation?

[Brian Michalk]

Oops.

Laurence Coen wrote:
> Are you calculating the area of the master cylinder piston?  If so isn't it 
> pi x r^2 not pi x d^2.  If the master cylinder is 5/8 diameter then the area 
> is ~ 0.3^2".  Then it would take 138 # of plunger force to make 450 PSI.
>
> Larry Coen
> N136LC
>
> P.S.: I have the original Matco brakes and master cylinders with no upgrades 
> and have hade no problems stopping and no meltdowns.
>
> ----- Original Message ----- 
> From: "Brian Michalk" <michalk at awpi.com>
> To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
> Sent: Thursday, February 14, 2008 11:43 AM
> Subject: Re: REFLECTOR: Leaking Brake Master cylinder
>
>
>   
>> Did not find 1/2" bore.
>> http://www.desertkarts.com/item107915.ctlg
>>
>> Might not be too difficult to sleeve and get new rubber bits.
>>
>> Brian Michalk wrote:
>>     
>>> Good question.
>>> What's the moment arm used on these cylinders.
>>>
>>> Desert Karts has 1/2" diameter cylinders, I think.
>>>
>>> NMFlyer1 at aol.com wrote:
>>>
>>>       
>>>> Brian,
>>>>
>>>> In my MATCO paperwork it says the calipers need 450 psi of force to
>>>> make rated torque on the brakes (600 MAX before calipers start to
>>>> bend). What I am curious about is if the factory master cylinders have
>>>> enough PSI for the MATCO requirement. If they are low, then an exact
>>>> replacement would be low also.
>>>>
>>>> They may work, but not be developing Max. Torque.. That would mean you
>>>> have to brake longer... = hotter.. etc.
>>>>
>>>> Just curious.
>>>>
>>>> Kurt
>>>>
>>>>
>>>> In a message dated 2/14/2008 9:23:37 A.M. Mountain Standard Time,
>>>> michalk at awpi.com writes:
>>>>
>>>>     Are you talking about max operating pressure?
>>>>
>>>>     pi * (5/8)^2 = 1.227 ~ 1.25 in^2
>>>>     needs 360lbs of plunger force.
>>>>
>>>>     Same diameter as the originals, so performance would be identical.
>>>>
>>>>
>>>>
>>>>
>>>>
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>>>>         
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>>     
>
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